import java.util.Scanner;

public class q39 {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        System.out.println("输入一个数");
        int a = input.nextInt();
        for (int b = 2; b <a/2; b++) {
            if (a % b == 0) {
                System.out.println(a + "不是质数");
                break;
            } if (a==b){
                System.out.println(a + "是质数");
                break;
            }
        }


    }
}
